1. Field of the Invention
The present invention relates to an apparatus and method for handling liquids or gases. In particular, the present invention relates to a double walled apparatus employing sensors and methods related thereto.
2. Related Art
Double walled tanks and pipes are commonly used in industry. The pipes typically comprise an inner wall and an outer wall separated by some annular space. The outer wall is generally designed to maintain the integrity of the pipe in the event of failure of the inner wall. The separation of the outer wall and inner wall is typically maintained by rings or spacers disposed between the two walls at various intervals along the length of the pipe or tank. By using such spacers or rings, there are areas along the pipe between spacers that are more susceptible to damage than those areas where the spacers are located. Since there is nothing between the inner and outer walls to prevent the collapse of the outer wall in these areas, it is possible that if the outer wall were subject to extreme external pressures it could easily collapse.
Pipes have been developed with wires maintained within the space between the walls of the pipe to detect the presence of liquid. This is done to overcome the need to visually inspect pipes and tanks on a regular basis. However, such systems report nothing more to an inspector than when liquid is present outside the inner wall of the pipe. There is presently no system that reports the constant conditions of the pipe or tank prior to failure of the inner wall. Typically, pipes and tanks having a double walled construction are buried in the ground, encased in concrete, or are in remote areas. When they are situated in such a manner, the pipe is virtually inaccessible for inspection or repair. It is possible to dig around the pipes to inspect them, but such undertakings are often very costly and do not reveal if there is a leak in the inner pipe. Additionally, digging around a pipe or tank could easily damage the pipe or tank. As a result, today the inner wall of a double walled pipe must be drained and some sort of robotic camera deployed to evaluate its structural integrity or locate any leaks.
Thus, there is a need in the art for a double walled apparatus that has a more secure and continuous construction for separating the inner and outer walls of the apparatus. There is further a need for a double walled apparatus employing sensors for providing data about the material conditions of the apparatus on a regular basis. There is further a need for a double walled apparatus that may be inspected or continuously monitored without visual inspection.